JPH0317037A - Production of barium alkoxide - Google Patents

Abstract

PURPOSE:To obtain the title substance from a readily available feed-stock by mixing a barium perchlorate solution in an organic solvent with an alkali metal alkoxide solution in an alcohol to exchange the perchlorate group with the alkoxy group. CONSTITUTION:Barium perchlorate is dissolved in an organic solvent such as methanol or acetone and mixed with an alkali metal alkoxide solution in an alcohol to effect the reaction between them lower than 60 deg.C whereby the title substance which is useful as an intermediate of ferrite, ceramic derivatives, catalyst for synthesis and others are obtained. In order to avoid the alkali metal alkoxide from remaining, the amount of barium perchlorate is preferably adjusted to about 1.2 time the stoichiometric amount. Isolation and purification are facilitated by adjusting the solvent composition so that either the subject substance or alkali perchlorate may separate and precipitate.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing barium alkoxides, which have many industrial uses as ferrites, ceramic dielectrics, catalysts for synthesis, and other intermediate raw materials. .

[Prior Art] Alkaline earth metal alkoxides, including barium, have conventionally been generally produced by directly reacting the alkaline earth metal with the corresponding alcohol; Possible materials are limited to those for which metallic materials can be obtained in some form, such as magnesium or calcium. The target barium alkoxide is extremely easy to produce if metallic barium is available. However, barium has few uses as a metal, and it is virtually impossible to obtain it on a commercial scale, and although it is expected to have many useful industrial uses, it has not been put to practical use. It is also possible to convert barium compounds other than metallic barium, such as halides, into alkoxides by exchange reaction with alkali metal alkoxides, but this method has poor solubility in organic solvents, except that bromides dissolve in methanol. Although it is possible to alkoxide it, it is difficult to purify and lacks practicality.

[Problem to be solved by the invention] As described above, if barium alkoxides are to be synthesized in a situation where it is difficult to obtain metallic barium, it is necessary to devise a method of converting barium alkoxides based on existing easily available barium compounds. Must. To this end, it is necessary to search for and find barium compounds that are soluble in organic solvents and capable of exchange reactions with alkali metal alkoxides.

[Means for Solving the Problems] In view of the above-mentioned current situation, as a result of intensive research, the present inventors found that barium perchlorate is a commonly used alcohol,
For example, it must be easily soluble or soluble in methanol, ethanol, propanols, butanols, and even alkoxy alcohols such as 2-methoxyethanol and 2-ethoxyethanol, and the solution itself must be stable and not susceptible to oxidation. Focusing on the fact that barium is easily ion-exchanged with alkali metal ions with almost no fear of deterioration, the present invention was constructed by estimating and confirming the possibility of barium alkoxide formation through an exchange reaction with alkali metal alkoxides. It is something that

That is, the present invention provides a method for producing barium alkoxides, which comprises mixing barium perchlorate dissolved in an organic solvent and an alcoholic solution of alkali metal alkoxides to exchange perchlorate groups and alkoxyl groups. It provides:

The present invention will be explained in detail below.

In the present invention, barium perchlorate is dissolved in an organic solvent, and the organic solvents used here include methanol, ethanol, 1-propanol, 2-propanol,
Alcohols having 1 to 4 carbon atoms such as 1-butanol and 2-butanol, 2-methoxyethanol. 2-ethoxyethanol, 2-proboxyethanol, 2-isobroboxyethanol, 2-butoxyethanol. 2-
Alkoxy alcohols such as isobutoxyethanol,
Examples include ketones such as acetone and methyl ethyl ketone, and acetate esters such as methyl acetate, ethyl acetate, proyl acetate, and butyl acetate.

Next, the barium perchlorate solution is mixed with an alkali metal alkoxide alcohol solution, and the alkali metal alkoxides used here specifically include lithium alkoxide, sodium alkoxide, and potassium alkoxide. In addition, alcohols for controlling these alkoxides include methanol, ethanol, 1-probanol, 2-probanol, and 1-probanol.
Alcohols having 1 to 4 carbon atoms such as butanol and 2-butanol, or 2-methoxyethanol, 2-ethoxyethanol, and 2-bropoxyethanol. 2-isoproboxyethanol, 2-butoxyethanol, 2-
Examples include alkoxy alcohols such as isobutoxyethanol.

The reaction is extremely rapid and can be completed sufficiently at room temperature, and there is no need for heating, but in order to accelerate the reaction, it is preferable to heat it to a level that does not induce oxidation by perchloric acid. It is.

If the temperature is 60° C. or lower, there will be almost no coloration due to oxidation, and it is desirable to carry out the reaction at this temperature or lower.

In order to avoid residual alkali metal alkoxide when proceeding with this reaction, it is desirable to use a slight excess of barium perchlorate compared to the theoretical amount in the compounding ratio during the reaction. leads to the contamination of perchloric acid groups, which not only makes purification difficult but also causes problems such as coloring due to oxidation. Therefore, the amount of barium perchlorate to be used relative to the alkali metal alkoxide is preferably between the theoretical amount and 1.2 times the amount.

Isolation and purification can also be facilitated by devising a solvent introduction so that either barium, alkoxide, or alkali perchlorate produced during this reaction is separated and precipitated. Perchlorates of alkali metals other than potassium are easily soluble in oxygen-containing organic solvents other than ethers, whereas barium alkoxides are soluble in solvents other than alcohols, such as acetone and methyl ethyl ketone. Since these solvents are insoluble or poorly soluble, the target barium alkoxide can be precipitated and isolated by mixing these solvents in advance or diluting them after the reaction is completed. When the alkali metal is potassium, we take advantage of the fact that the potassium perchlorate produced by the exchange reaction is extremely poorly soluble, and devised a method so that this potassium perchlorate precipitates and precipitates at the same time as it is produced, leaving the barium alkoxide on the solution side. This allows you to separate the two. This barium alkoxide solution is either concentrated or isolated by precipitation by adding a poor solvent such as acetone or methyl ethyl ketone. When using a ketone solvent as a poor solvent, if it is left with an alkoxide for a long time, the ketone solvent will
Since quantification and trimerization may occur and colored substances may be produced as by-products, it is desirable to carry out separation treatment within as short a time as possible, thereby preventing impurity of the alkoxide itself.

[Effects of the Invention] As mentioned above, in the present invention, barium perchlorate, which is a very common compound, is used to carry out an exchange reaction with an alkali metal alkoxide, without using barium metal, which is difficult to obtain, as a raw material. This process converts barium anolecoxide into the desired barium anolecoxide, which facilitates its use as an intermediate raw material for ferrite, ceramic dielectrics, synthesis catalysts, and other materials.

[Examples] Hereinafter, the content of the present invention will be explained in detail and concretely using Examples, but the scope of technical application of the present invention is not limited thereby.

Example 1 300 ml of sufficiently dehydrated anhydrous methanol was placed in a 2000 ml four-necked flask, and N2 gas was introduced to create an inert atmosphere. Next, 23 g of high-purity metallic sodium was weighed and added to the solution at room temperature to prepare a sodium methoxide solution. For this sodium methoxide solution, anhydrous barium perchlorate 1
When a solution of 68 g dissolved in 1200 ml of acetone was injected at room temperature while stirring, barium methoxide precipitated simultaneously with the injection, and the system turned into a cloudy white slurry. After continuing the reaction at room temperature for 2 hours, it was filtered in an inert atmosphere with N2 gas to obtain barium methoxide as a white crystalline substance. To remove some perchloric acid mixed in, redisperse with acetone, refiltrate, and dry under reduced pressure.7
Barium methoxide was obtained as 9.2 g of white crystalline powder.

The yield was 79.5% based on sodium.

The obtained barium methoxide was extremely easily soluble in methanol and soluble in other alcohols, but was insoluble or poorly soluble in acetone, methyl ethyl ketone, ethers, and aromatic systems such as benzene and toluene. .

Similar results were obtained by injecting a sodium methoxide solution into an acetone solution of barium perchlorate instead of injecting the barium perchlorate solution into the sodium methoxide solution in the above example.

Example 2 N2 gas was introduced into a 1000 ml fourth flask to create an inert atmosphere, and then 200 ml of sufficiently dehydrated ethylene glycol dimethyl ether and 39 ml of metallic potassium were added.
g was weighed out, and 200 ml of absolute ethanol was slowly injected for reaction to prepare a potassium ethoxide solution.

A solution prepared by dissolving 168 g of anhydrous barium perchlorate in 400 ml of absolute ethanol was injected into the potassium ethoxide solution at room temperature while stirring. As the reaction progressed through injection, potassium perchlorate was gradually formed and the system became a cloudy slurry. After the reaction was aged at room temperature for 4 hours, it was filtered in an inert atmosphere with N2 gas to obtain a solution of barium ethoxide from which precipitated potassium perchlorate had been removed. The solvent was removed from this solution under reduced pressure to obtain barium ethoxide 110 as a white powder.
I got g. The yield was 96.8% over metallic potassium. This barium ethoxide is easily soluble in alcohols such as methanol and ethanol, and alkoxy alcohols such as 2-methoxyethanol, but ethers such as ethyl ether and tetrahydrofuran, acetone, methyl ethyl ketone, etc. It was insoluble or poorly soluble in ketones, benzene, toluene, and other aromatic systems.

Example 3 The alcohol used in Example 2 was replaced with normal butanol (1
-butanol), the same operation was performed, and the barium 1-butoxide crystalline powder 136
I got g. The yield based on metallic potassium was 96.1%. This barium 1-ptoxide was easily soluble in alcohols and alkoxy alcohols, and poorly soluble in ethers, ketones, and aromatic solvents.

Example 4 The alcohol used in Example 2 was replaced with 2-methoxyethanol (methylcellosolve) and the same procedure was carried out to obtain 140 g of light brown crystals of barium 2-methoxyethoxide. Obtained. The yield based on metallic potassium was 97.4%. This barium 2
-Methoxyethoxide is easily or soluble in alcohols, alkoxyalcohols, aromatic and other solvents, but is insoluble or poorly soluble in aliphatic hydrocarbons.

Example 5 A 1000 ml four-necked flask was placed in an inert dry atmosphere as in the previous example, and then anhydrous 1-probanol 2
00 ml was weighed out, and 7 g of metallic lithium was added and completely dissolved to form lithium proboxide. Next, acetic acid normal
180 g of anhydrous barium perchlorate dissolved in 1000 ml of Provil was injected at room temperature. As the injection progressed, the state changed from a cloudy slurry to a crystalline slurry.

After the injection was completed, the reaction was allowed to mature at room temperature for 4 hours, and the crystalline precipitate was collected under an inert atmosphere to obtain barium proboxoxide. In order to remove some perchloric acid mixed in, dispersion washing was performed in probyl acetate, refiltration, and drying under reduced pressure at room temperature to avoid reaction between alkoxide and ester, yielding 99.2 g of barium 1 as a white crystalline powder. - Propoxide was obtained. Yield is 77% based on metallic lithium
．． It was 8%.

Procedural amendment

Claims (1)

[Claims] 1. A method for producing barium alkoxides, which comprises mixing barium perchlorate dissolved in an organic solvent and an alcoholic solution of alkali metal alkoxides to exchange perchlorate groups and alkoxyl groups.